Highly purified solubilized FSH receptors will be isolated and conditions optimized for stabilizing those receptors. Specific antibody to solubilized FSH receptor will be used to study biogenesis and degradation of specific receptors. Studies characterizing the mechanism of hormone-induced refractoriness of hormonal-responsive cells will be carried out. A variety of potential biochemical possibilities will be explored. Finally, the intracellular role of the subunits of cyclic AMP-dependent protein kinases will be examined in gonadotropin-responsive cells to ascertain whether any analogies can be made between known intracellular mechanisms for steroid-responsive cells and gonadotropin-mediated mechanisms.